The present disclosure relates to a driving unit using a polymer actuator element, and a lens module as well as an image pickup device with such a driving unit.
In recent years, for example, portable electronic devices such as a portable telephone, and a personal computer (PC), or a PDA (Personal Digital Assistant) have become remarkably multifunctional, and a portable electronic device equipped with a lens module thereby having an image pickup function has become common. In such a portable electronic device, focusing and zooming are performed by moving a lens in the lens module to an optical axis direction.
In general, a way of moving the lens in the lens module by using a voice coil motor or a stepping motor as a drive section is common. Meanwhile, recently, a device employing a polymer actuator element as a drive section has been developed from the viewpoint of miniaturization (see, for example, Japanese Unexamined Patent Application Publications No. 2006-293006 and No. 2006-172635). The polymer actuator element is an element in which, for example, an ion exchange resin film is interposed between a pair of electrodes. In this polymer actuator element, the ion exchange resin film is displaced in a direction orthogonal to a film surface, due to occurrence of a potential difference between the pair of electrodes.